The root-lesion—or meadow—nematode has been found widely scattered in California by United States Department of Agriculture and Experiment Station workers. In 1941 it was found associated with die-back of bearing sweet cherry trees in Riverside County. About the same time it was found on walnut trees showing poor vigor in Ventury County. Since then it has been identified on walnuts in several southern California counties and also in the San Joaquin, Sacramento, and Santa Clara valleys and Sierra Nevada foothills. Fig and olive roots have been reported frequently infested with this nematode. Apple, almond, peach, pear, plum, and quince roots have been reported infested.

The above progress report is based on Research Projects No. 613-J and 1385.